Abstract: For non-contact face mechanical seal, the stability of seal gap is a key parameter to keep the seal running steady. In the present paper, the stability of laser textured gas-lubricated non-contact mechanical seal (LST-MS) was numerically analyzed compared with spiral face mechanical seal. A series of simulations were carried out to analyze the influence of clearance, pitch angle and disturbance on seal performance. Numerical results showed that the dynamic effect was very weak for LST-MS, which led to contact friction and wear at start off of the mating seal faces; LST-MS has an evener pressure distribution on seal face, which will reduce disturbance of open force induced by pitch angle; LST-MS has a smaller gas film stiffness as well as a clearance disturbance amplitude, which meant the seal had less face contact and friction during running.